Gas pressure regulators are generally classified into two types: direct-acting and indirect-acting. A direct-acting regulator consists of a measuring element (diaphragm), a transmission component (valve stem), and a regulating mechanism (valve); an indirect-acting regulator consists of a main regulator, a pilot valve, and an exhaust valve.
The working principle of a direct-acting regulator is that when the outlet pressure decreases, the force on the lower side of the diaphragm is less than the force of the weight on the diaphragm or the spring, causing the diaphragm to descend, the valve disc to move downward, and the valve to open wider to increase flow, thereby restoring the outlet pressure. Conversely, when the outlet pressure increases, the valve closes to reduce flow. Typical models, such as the RTZ1-/0.4Q/QF/BQF series, are mainly used for medium- and low-pressure primary pressure regulation in urban gas transmission and distribution systems, and include inlet and outlet valves, filters, and overpressure shut-off functions. The RTZ//A series uses spring-loaded control and is suitable for residential communities, gas boilers, and other similar applications.
The working principle of an indirect-acting pressure regulator is as follows: when the outlet pressure is lower than the set value, the pilot valve opens, and gas is supplied to the space under the diaphragm of the main pressure regulator, causing the main pressure regulator valve to open wider to increase the flow rate; when the outlet pressure exceeds the set value, the pilot valve closes, the vent valve opens to release gas, and the main pressure regulator valve closes less. A typical model, such as RTJ-52/50GK, is mainly used for pressure regulation in high, medium, and low pressure pipeline networks and can be configured as a single-circuit bypass or dual-circuit plus bypass cabinet-type pressure regulating system.